Aug. 6 (UPI) -- Beyoncé says Jay-Z was her rock after her emergency C-section last year.

The 36-year-old singer recalled in the September issue of Vogue how Jay-Z was a source of strength following the difficult birth of their twins, daughter Rumi and son Sir.

"I was 218 pounds the day I gave birth to Rumi and Sir," Beyoncé told the magazine. "I was swollen from toxemia and had been on bed rest for over a month. My health and my babies' health were in danger, so I had an emergency C-section."

"We spent many weeks in the NCIU," she said. "My husband was a soldier and such a strong support system for me. I am proud to have been a witness to his strength and evolution as a man, a best friend, and a father. I was in survival mode and did not grasp it all until months later."

Beyoncé gave birth to Rumi and Sir in June 2017. She said she's come to embrace her curvier figure as she recovers from her C-section.

"I accepted what my body wanted to be. After six months, I started preparing for Coachella," the star recalled. "But I was patient with myself and enjoyed my fuller curves. My kids and husband, did too."

"To this day my arms, shoulders, breasts, and thighs are fuller. I have a little mommy pouch, and I'm in no rush to get rid of it. I think it's real," she said.

Beyoncé and Jay-Z are also parents to 6-year-old daughter Blue Ivy. The couple married in April 2008.

Tyler Mitchell, 23, photographed Beyoncé for the issue of Vogue. Mitchell is the first African-American photographer to shoot a cover for the magazine.

"This is as much about forming firsts as it is about leaving legacies," Mitchell captioned a photo of the cover on Instagram. "Here's @beyonce by me for the September 2018 issue of American Vogue. Honored to have worked with such an icon."